Geisha balls Magnetic - new and modern era of Kegel muscle exercise.Geisha balls Magnetic are simple and clear to use. The package contains 4 balls of different weight. The set consists of two pink balls 27 g / 0.95 oz; and two black balls 15 g / 0.55 oz. The core idea of the exercise is to start with one black ball on a silicone string and then gradually increase the weight by magnetizing 1 ball at a time. It is the same you do during your workout at the gym. Geisha Balls Magnetic allows to do 7 levels of workout - from 15 g /0.55 oz to 84 g/ 3 oz. After this experienced users will work out only with the balls without a string. Materials: 100 % Medical grade silicone. Weight of 4 magnetized balls: Two balls 27 g / 0.95 oz; Two balls 15 g / 0.55 oz Size - 22 mm / 0.87 in and 18 mm / 0.71 in in diameter The balls have 1 year warranty.